US10113999B2ActiveUtilityA1
Method and a device for detecting a substance
Est. expiryMar 7, 2034(~7.7 yrs left)· nominal 20-yr term from priority
G01N 33/004G01N 21/3504G01J 3/42G01N 2201/061G01N 21/031G01J 3/26G01N 21/85G01N 2201/068
37
PatentIndex Score
0
Cited by
14
References
23
Claims
Abstract
A device for detecting a substance includes a light source arranged to emit a light signal through a sample cell, wherein the sample cell is arranged to temporally house a sample compound having a portion of the substance, and an optical processing module arranged to detect the light signal emitted through the sample cell to identify physical attributes of the light signal altered by the sample compound, wherein the physical attributes of the light signal altered by the sample compound is processed so as to detect the substance within the sample compound.
Claims
exact text as granted — not AI-modifiedThe invention claimed is:
1. A device for detecting a substance comprising:
a light source arranged to emit a light signal through a sample cell, wherein the sample cell is arranged to temporally house a sample compound having a portion of the substance; and
an optical processing module arranged to detect the light signal emitted through the sample cell to identify physical attributes of the light signal altered by the sample compound at multiple wavelengths, the light signal is at least partially absorbed by the sample compound in the sample cell;
wherein the physical attributes of the light signal altered by the sample compound are processed by fitting the physical attributes at the multiple wavelengths to a reference absorption spectrum of the substance so as to detect the substance within the sample compound; and wherein the optical processing module includes a light sensor and a micro-electric-mechanical-system arranged to enable the light sensor to detect the physical attributes of the altered light signal at the multiple wavelengths; and
wherein the optical processing module is further arranged to process the detected physical attributes using an iterative retrieval process so as to correct a non-linear effect of the light signal altered by the sample compound in a dispersive infrared spectroscopy measurement process; the iterative retrieval process includes:
a convolution process of high resolution cross sections with an instrument spectral resolution of the optical processing module; and
a second order polynomial in a fitting process between a measured absorption spectrum and a reference absorption spectrum of the sample compound; wherein the fitting process is carried out using a modified absorption cross section represented by:
σ
i
,
n
+
1
(
λ
)
=
-
ln
(
exp
(
-
L
·
σ
i
,
n
(
λ
)
·
c
i
,
n
)
*
F
(
λ
′
)
)
L
·
c
i
,
n
where L represents a distance that the light signal passes through the sample compound, c represents a concentration of the sample compound, and F represents an instrument function associated with an influence of the instrument on the spectra including the sampling process.
2. A device for detecting a substance in accordance with claim 1 , wherein the sample compound includes a gas.
3. A device for detecting a substance in accordance with claim 1 , wherein the optical processing comprises a light sensor.
4. A device for detecting a substance in accordance with claim 3 , wherein the light sensor includes a pyroelectric sensor.
5. A device for detecting a substance in accordance with claim 4 , wherein the light sensor further includes a Fabry-Pérot interferometer.
6. A device for detecting a substance in accordance with claim 5 , wherein the pyroelectric sensor is integrated with the Fabry-Pérot interferometer.
7. A device for detecting a substance in accordance with claim 3 , wherein the light sensor is a Fabry-Pérot interferometer sensor.
8. A device for detecting a substance in accordance with claim 1 , wherein the physical attributes include a signal strength of the light signal at one or more wavelengths emitted by the light source.
9. A device for detecting a substance in accordance with claim 8 , wherein the physical attributes include an optical spectrum of the light signal emitted by the light source.
10. A device for detecting a substance in accordance with claim 9 , wherein the light source is a broad band infrared light source.
11. A device for detecting a substance in accordance with claim 10 , wherein the light signal is in a range of wavelengths between 3 μm to 5 μm.
12. A device for detecting a substance in accordance with claim 1 , wherein the optical processing module further comprises a photo detector and two layers of glass separated by a variable distance controlled by a variable electrical signal.
13. A device for detecting a substance in accordance with claim 2 , wherein the sample cell is a gas cell arranged to connect with a gas flow system for flowing the gas into and out of the gas cell.
14. A device for detecting a substance in accordance with claim 13 , wherein the air flow system comprises an HEPA filter at an inlet of the gas cell for blocking aerosol from entering the gas cell.
15. A device for detecting a substance in accordance with claim 1 , the substance includes a greenhouse gas.
16. A device for detecting a substance in accordance with claim 1 , the substance includes at least one of carbon dioxide, methane, nitrous oxide or water.
17. A method for detecting a substance comprising the steps of:
temporally housing a sample compound having a portion of the substance;
emitting a light signal through the sample compound such that the light signal is at least partially absorbed by the sample compound;
manipulating with a micro-electro-mechanical-system so as to enable a detection of the light signal at multiple wavelengths;
detecting the light signal at the multiple wavelengths emitted through the sample-compound; and
processing the detected light signal;
wherein physical attributes of the light signal altered by the sample compound is identified and processed by fitting the physical attributes at the multiple wavelengths to a reference absorption spectrum of the substance so as to detect the substance within the sample compound; and
wherein the identified physical attributes are further processed using an iterative retrieval process such that a non-linear effect of the light signal altered by the sample compound in a dispersive infrared spectroscopy measurement process is corrected; the iterative retrieval process includes:
a convolution process of high resolution cross sections with an instrument spectral resolution of an optical processing module arranged to emit and to detect the light signal; and
a second order polynomial in a fitting process between a measured absorption spectrum and a reference absorption spectrum of the sample compound; wherein the fitting process is carried out using a modified absorption cross section represented by:
σ
i
,
n
+
1
(
λ
)
=
-
ln
(
exp
(
-
L
·
σ
i
,
n
(
λ
)
·
c
i
,
n
)
*
F
(
λ
′
)
)
L
·
c
i
,
n
where L represents a distance that the light signal passes through the sample compound, c represents a concentration of the sample compound, and F represents an instrument function associated with an influence of the instrument on the spectra including the sampling process.
18. A method for detecting a substance in accordance with claim 17 , wherein the light signal is detected by a Fabry-Pérot interferometer sensor.
19. A method for detecting a substance in accordance with claim 17 , wherein the physical attribute includes a signal strength of the light signal emitted at one or more wavelengths.
20. A method for detecting a substance in accordance with claim 19 , wherein the physical attribute includes an optical spectrum of the emitted light signal.
21. A method for detecting a substance in accordance with claim 17 , wherein the light source is emitted by a broad band infrared light source.
22. A method for detecting a substance in accordance with claim 17 , wherein the sample compound includes a gas, and is temporally housed in a gas cell arranged to connect with an air flow system for flowing the gas into and out of the gas cell.
23. A method for detecting a substance in accordance with claim 17 , the substance includes a greenhouse gas.Cited by (0)
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